The Solidarity trade union in November demanded a wage increase of PLN 300 (EUR 68) a month in 2016 plus a one-off PLN 2,500 (EUR 570) bonus for workers for the previous year.

Unionists claim that managers have deliberately stalled wage negotiations and have warned they will start a protest if the company fails to reveal its plans within a week.

The company has said that it is prepared to hold talks.

"We are ready to present the unionists a comprehensive explanation of the employer’s position in respect of all their demands," ArcelorMittal Poland spokeswoman Sylwia Winiarek told the PAP news agency.

She added that because of the Christmas break it was not possible to launch talks earlier.

ArcelorMittal Poland is the country’s largest steel producer. The group includes the Zdzieszowice Coke Plant, the largest coke producer in Europe.

ArcelorMittal Poland employs over 11,000 people, and together with its subsidiaries more than 14,000. (pk)